Welcome to the forum. You sound like you plan to do all your RVing on the interstate. :)
Don't be too concerned about the narrow, steep roads, etc.. Just slow down and take your time.
Find a local narrow and winding road you can use to practice. Drive it a few times before your trip. Be patient, you will be okay and safe.
If you have a string of traffic behind you, find a wide spot to pull over and allow traffic to pass.
The day we bought our 37' Southwind, I got off the interstate after about 10 miles and used two lane roads to get home. It took a couple hours.
Drive it, it's the only way to learn.
Be safe and enjoy your trip.